Field of Invention
The present invention relates to a urea solution pumping module which pumps a urea solution stored in a urea solution tank to an injector at a predetermined pressure so that the injector injects the urea solution to exhaust gas in an exhaust line.
Description of Related Art
Environmentally-friendly vehicles have been globally developed, and exhaust gas emission standards for vehicles of the respective countries have gradually become stricter. In addition, due to regulations on carbon dioxide, vehicle makers are developing environmentally-friendly diesel vehicles.
Nitrogen oxide and particulate matters are cores of the exhaust gas emission standards for the diesel vehicles, and particularly, as a technology of reducing nitrogen oxide, an LNT and a UREA-SCR attract attention. Particularly, the UREA-SCR is useful to reduce nitrogen oxide emitted from diesel engines of large vehicles.
The UREA-SCR is a selective reduction system in which a harmless urea solution is injected into an exhaust system, the injected urea solution is converted into ammonia by thermal decomposition and hydrolysis, and the converted ammonia reacts with nitrogen oxide in exhaust gas so as to be converted into harmless substances such as water and nitrogen, and the UREA-SCR requires a system for separately storing and supplying the urea solution.
The system for storing and supplying the urea solution includes a urea solution tank, a pump, an injection port, piping, wiring, and various sensors, the pump particularly requires a structure of stably pumping a strong basic urea solution, and it is necessary to downsize the urea solution tank in order to reduce a length in an up and down direction.
The information disclosed in this Background section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.